I have argued that there is a human right not to suffer from poverty and sought to identify the (negative and positive) obligations entailed by this right. See
 ‘Global Poverty and Human Rights: the Case for Positive Duties’ in Freedom from Poverty as a Human Right: Who Owes What to the Very Poor? (Oxford: Oxford University Press, 2007), edited by Thomas Pogge, pp.275-302.
One key question is: What policies would best promote the condition of the world's poor. I have examined 12 policies (including, among others, open borders, a Tobin tax, reducing barriers to trade, among others) and some of the relevant literature here:
 ‘Global Justice: From Theory to Practice’, Globalizations, vol.3 no.2 (2006), pp.121-137. This has been reprinted in Globalization and the Global Politics of Justice (London: Routledge, 2008) edited by Barry Gills.